(1) Field of the Invention
The present invention relates to a technique for a network in which a display device such as a television, a reproduction device, and an audio output device are connected to each other via an input and output switching device. Specifically, video, etc. which is outputted by a device and displayed on the display device is viewed. The present invention relates to an input and output switching device which appropriately switches input of sound data according to which device is the device currently used for such viewing.
(2) Description of the Related Art
In recent years, improvement of picture quality and sound quality in AV devices has progressed such that, even in ordinary households, blu-ray disc (BD) players, set top boxes (STBs), and the like, have become popular and it has become possible to enjoy what is called high definition (HD) video.
Furthermore, with the widespread use of networks and HDMI (see High-Definition Multimedia Interface, Non-patent Reference I (HDMI Standard (High-Definition Multimedia Interface Specification Version 1.3a)), link functions which provide various added functions by having AV devices perform operations in conjunction with each other are becoming popular. Among such link functions, there is a function where, for example, when reproduction by the BD player is started, the power of a television turns ON and the input of the television, AV amplifier, and so on, automatically switches to the BD player. In other words, as a link function, there is a link function which, though the above-described switching, allows content reproduced by the BD player to be viewed simply, without having to operate the television, AV amplifier, and so on. Generally, such a function is called one-touch play.
In order to implement a link function such as the one-touch play, and so on, the HDMI Standard (Non-Patent Reference 1) defines a device control protocol referred to as Consumer Electronic Control (CEC).
Furthermore, in place of HDMI which is a wired interface, interfaces such as wireless HD (see Non-patent Reference 2 (Wireless HD Specification Overview) and so on) for transmitting HD video using wireless communication are becoming popular.
In order to allow such wired interfaces to be used by existing HDMI-compliant devices, there is a wireless HDMI converter which performs conversion between a wireless interface and HDMI.
An example of the operation of a wireless HDMI converter shall be described using FIG. 6 to FIG. 9.
FIG. 6 is a diagram showing an example of a configuration of an AV device network using a wireless HDMI converter 61 having one HDMI input (system 6).
FIG. 7 is a diagram showing an example of a configuration of the wireless HDMI converter 61 in FIG. 6.
First, the operation of the wireless HDMI converter 61 when viewing using a BD player 62, in the AV device network shown in FIG. 6 shall be described below.
An HDMI input interface 23a receives video and audio data 62d from the BD player 62, via an HDMI cable 15. Then, upon such receiving, the HDMI input interface 23a outputs the received video and audio data 62d to a wireless interface 71.
The wireless interface 71 transmits the outputted video and audio data 62d to a TV 11, using wireless communication. It should be noted that, at this time, the wireless interface 71 performs processing necessary for wireless communication such as, for example, establishing a connection with the TV 11, securing bandwidth, converting packet formats, and so on.
In this way, the video and audio (video and audio data 62d in FIG. 7) reproduced by the BD-player 62 (FIG. 6) can be viewed using the TV 11 (FIG. 6), via wireless communication.
FIG. 8 is a diagram showing an example of a configuration of an AV device network using a wireless HDMI converter 81 having one HDMI input and an optical audio output (system 8).
FIG. 9 is a diagram showing an example of a configuration of the wireless HDMI converter 81 in FIG. 8.
Furthermore, among wireless interfaces, there is a wireless interface that is capable of transmitting audio data in a direction opposite to the transmission direction of normal video and audio data. In this case, as shown in FIG. 8, for example, the wireless HDMI converter 81 and an AV amplifier 82 are connected using an optical audio cable 16.
Hereinafter, the operation of the wireless HDMI converter 81 in FIG. 8 shall be described using FIG. 9.
(i) Viewing Using the BD Player 62
The BD player 62 transmits the video and audio data 62d to the AV amplifier 82 via the HDMI cable 15.
Then, the AV amplifier 82 transmits the received video and audio data 62d to the wireless HDMI converter 81 via the HDMI cable 15. In addition, at this time, the AV amplifier 82 extracts the audio data inside the video and audio data 62d, and outputs the audio of the extracted audio data.
In the same manner as the HDMI input interface 23a of the wireless HDMI converter 61 shown in FIG. 7, upon receiving the video and audio data 62d from the BD player 62 via the HDMI cable 15, the HDMI input interface 23a of the wireless HDMI converter 81 outputs the received video and audio data 62d to the wireless interface 91.
The wireless interface 91 transmits the outputted video and audio data 62d to the TV 11, using wireless communication. It should be noted that, at this time, the wireless interface 91 performs processing necessary for wireless communication such as, for example, establishing a connection with the TV 11, securing bandwidth, converting packet formats, and so on.
(ii) Viewing Using the TV 11
The wireless interface 91 receives audio data 11d from the TV 11 using wireless communication, and outputs the received audio data 11d to an optical audio output interface 24. It should be noted that, at this time, the wireless interface 91 performs processing necessary for wireless communication such as, for example, establishing a connection with the TV 11, securing bandwidth, converting packet formats, and so on, in the same manner as in above-described (i).
The optical audio output interface 24 transmits the audio data 11d outputted by the wireless interface 91, to the AV amplifier 82 via the optical audio cable 16.
In this manner, it is possible to listen to audio using the AV amplifier 82 in either the case of viewing video and audio (video and audio data 62d) generated by the BD player 62 using the TV 11 ((i) described above), or the case of viewing using the TV 11 ((ii) described above).
FIG. 10 is a diagram showing an example of a network in which a home theater 14 and an STB 13 are present (system 10).
On the other hand, among BD players, there is a device which is called a home theater and includes the function of an AV amplifier. Generally, a home theater does not have an HDMI input. As such, a user that wants to use an STB (Set Top Box) and a home theater simultaneously adopts a connection configuration shown in FIG. 10. Specifically, an STB 13 and a home theater 14 are each connected to an HDMI input of a TV 101. Then, when viewing using the STB 13, the TV 101 extracts audio data 101d from audio and video data 13d received from the STB 13 via the HDMI cable 15, and transmits the extracted audio data 101d to the home theater 14 via the optical audio cable 16. It should be noted that Patent Reference 1 (Japanese Unexamined Patent Application Publication No. 2009-182912) describes a technique for extracting (separating) audio data.
It should be noted that, with regard to prior art, “Japanese Unexamined Patent Application Publication No. 2009-182912” is cited as Patent Reference 1. Furthermore, “HDMI Standard (High-Definition Multimedia Interface Specification Version 1.3a” is cited as Non-patent Reference 1. Furthermore, “Wireless HD Specification Overview” is cited as Non-patent Reference 2.